[PATCH] b/arch/x86/mm/pti.c - make local symbols static

[PATCH] b/arch/x86/mm/pti.c - make local symbols static

[Valdis Klētnieks]

With 'make C=2 W=1', sparse and gcc both complain:

  CHECK   arch/x86/mm/pti.c
arch/x86/mm/pti.c:84:3: warning: symbol 'pti_mode' was not declared. Should it be static?
arch/x86/mm/pti.c:605:6: warning: symbol 'pti_set_kernel_image_nonglobal' was not declared. Should it be static?
  CC      arch/x86/mm/pti.o
arch/x86/mm/pti.c:605:6: warning: no previous prototype for 'pti_set_kernel_image_nonglobal' [-Wmissing-prototypes]
  605 | void pti_set_kernel_image_nonglobal(void)
      |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

And indeed, the function at line 605 is only used locally. 'pti_mode' is more
subtle - there is another pti_mode in drivers/hwtracing/intel_th/pti.c, but
it's an array declared static, not an enum

Make both variables static.

Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>

---
diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
index 4fee5c3003ed..139b28a01ce4 100644
--- a/arch/x86/mm/pti.c
+++ b/arch/x86/mm/pti.c
@@ -77,7 +77,7 @@ static void __init pti_print_if_secure(const char *reason)
 		pr_info("%s\n", reason);
 }
 
-enum pti_mode {
+static enum pti_mode {
 	PTI_AUTO = 0,
 	PTI_FORCE_OFF,
 	PTI_FORCE_ON
@@ -602,7 +602,7 @@ static void pti_clone_kernel_text(void)
 	set_memory_global(start, (end_global - start) >> PAGE_SHIFT);
 }
 
-void pti_set_kernel_image_nonglobal(void)
+static void pti_set_kernel_image_nonglobal(void)
 {
 	/*
 	 * The identity map is created with PMDs, regardless of the

Re: [PATCH] b/arch/x86/mm/pti.c - make local symbols static

[Dave Hansen]

> Make both variables static.

"pti_set_kernel_image_nonglobal(void)" is an awfully funny looking
variable. ;)

> Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
> 
> ---
> diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
> index 4fee5c3003ed..139b28a01ce4 100644
> --- a/arch/x86/mm/pti.c
> +++ b/arch/x86/mm/pti.c
> @@ -77,7 +77,7 @@ static void __init pti_print_if_secure(const char *reason)
>  		pr_info("%s\n", reason);
>  }
>  
> -enum pti_mode {
> +static enum pti_mode {

I'm struggling to figure out why we would want to do this.  If there's a
really good reason, I think we probably need to do it en masse:

$ grep -r '^enum.{' arch/x86/ | wc -l
48

>  	PTI_AUTO = 0,
>  	PTI_FORCE_OFF,
>  	PTI_FORCE_ON
> @@ -602,7 +602,7 @@ static void pti_clone_kernel_text(void)
>  	set_memory_global(start, (end_global - start) >> PAGE_SHIFT);
>  }
>  
> -void pti_set_kernel_image_nonglobal(void)
> +static void pti_set_kernel_image_nonglobal(void)

Yes, this function should be static.

Re: [PATCH] b/arch/x86/mm/pti.c - make local symbols static

[Thomas Gleixner]

On Tue, 12 Mar 2019, Dave Hansen wrote:

> > Make both variables static.
> 
> "pti_set_kernel_image_nonglobal(void)" is an awfully funny looking
> variable. ;)
> 
> > Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
> > 
> > ---
> > diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
> > index 4fee5c3003ed..139b28a01ce4 100644
> > --- a/arch/x86/mm/pti.c
> > +++ b/arch/x86/mm/pti.c
> > @@ -77,7 +77,7 @@ static void __init pti_print_if_secure(const char *reason)
> >  		pr_info("%s\n", reason);
> >  }
> >  
> > -enum pti_mode {
> > +static enum pti_mode {
> 
> I'm struggling to figure out why we would want to do this.  If there's a
> really good reason, I think we probably need to do it en masse:

Because its:

enum pti_mode {
 ....
} pti_mode;

So that's both enum and variable declaration. 

> $ grep -r '^enum.{' arch/x86/ | wc -l
> 48

In the other cases it's a enum declaration without declaring a variable at
the same time. Making them static would be obviously bogus.

Thanks,

	tglx

 

Re: [PATCH] b/arch/x86/mm/pti.c - make local symbols static

[Thomas Gleixner]

[-- Attachment #1: Type: text/plain, Size: 265 bytes --]

Valdis,

On Tue, 12 Mar 2019, Valdis Klētnieks wrote:

I've applied the lot, but I had to fixup the subject lines.

# git log path/to/file

gives you a decent hint on what the usual prefix and format is.

 'b/arch/x86/mm/pti.c -'

is obviously not.

Thanks,

	tglx

[tip:x86/urgent] x86/mm/pti: Make local symbols static

[tip-bot for Valdis Kletnieks]

Commit-ID:  4fe64a62e04cfb2dc1daab0d8f05d212aa014161
Gitweb:     https://git.kernel.org/tip/4fe64a62e04cfb2dc1daab0d8f05d212aa014161
Author:     Valdis Kletnieks <valdis.kletnieks@vt.edu>
AuthorDate: Tue, 12 Mar 2019 03:47:53 -0400
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Fri, 22 Mar 2019 13:31:28 +0100

x86/mm/pti: Make local symbols static

With 'make C=2 W=1', sparse and gcc both complain:

  CHECK   arch/x86/mm/pti.c
arch/x86/mm/pti.c:84:3: warning: symbol 'pti_mode' was not declared. Should it be static?
arch/x86/mm/pti.c:605:6: warning: symbol 'pti_set_kernel_image_nonglobal' was not declared. Should it be static?
  CC      arch/x86/mm/pti.o
arch/x86/mm/pti.c:605:6: warning: no previous prototype for 'pti_set_kernel_image_nonglobal' [-Wmissing-prototypes]
  605 | void pti_set_kernel_image_nonglobal(void)
      |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

pti_set_kernel_image_nonglobal() is only used locally. 'pti_mode' exists in
drivers/hwtracing/intel_th/pti.c as well, but it's a completely unrelated
local (static) symbol.

Make both static.

Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/27680.1552376873@turing-police


---
 arch/x86/mm/pti.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
index 4fee5c3003ed..139b28a01ce4 100644
--- a/arch/x86/mm/pti.c
+++ b/arch/x86/mm/pti.c
@@ -77,7 +77,7 @@ static void __init pti_print_if_secure(const char *reason)
 		pr_info("%s\n", reason);
 }
 
-enum pti_mode {
+static enum pti_mode {
 	PTI_AUTO = 0,
 	PTI_FORCE_OFF,
 	PTI_FORCE_ON
@@ -602,7 +602,7 @@ static void pti_clone_kernel_text(void)
 	set_memory_global(start, (end_global - start) >> PAGE_SHIFT);
 }
 
-void pti_set_kernel_image_nonglobal(void)
+static void pti_set_kernel_image_nonglobal(void)
 {
 	/*
 	 * The identity map is created with PMDs, regardless of the